The present disclosure relates to a multilayer ceramic electronic component to be embedded in a board, and a printed circuit board having the multilayer ceramic electronic component embedded therein.
As electronic circuits have become highly densified and highly integrated, a mounting space for passive elements mounted on a printed circuit board (PCB) has become insufficient. In order to solve this problem, ongoing efforts have been made to implement components able to be installed within a board, such as embedded devices. Particularly, various methods have been proposed for installing a multilayer ceramic electronic component used as a capacitive component within a board.
As one of a variety of methods of installing a multilayer ceramic electronic component within a board, the same dielectric material used for a multilayer ceramic electronic component is used as a material for a board and a copper wiring, or the like, is used as an electrode. Other methods for implementing an embedded multilayer ceramic electronic component include forming an embedded multilayer ceramic electronic component by forming a polymer sheet having high-k dielectrics or a dielectric thin film within a board, installing a multilayer ceramic electronic component within a board, and the like.
In general, a multilayer ceramic electronic component includes a plurality of dielectric layers made of a ceramic material and internal electrodes interposed therebetween. By disposing a multilayer ceramic electronic component within a board, an embedded multilayer ceramic electronic component having high capacitance may be implemented.
In order to manufacture a printed circuit board (PCB) including an embedded multilayer ceramic electronic component, a multilayer ceramic electronic component may be inserted into a core board, and via holes are required to be formed in an upper stacked plate and a lower stacked plate by using a laser in order to connect board wirings and external electrodes of the multilayer ceramic electronic component. Laser beam machining, however, considerably increases manufacturing costs of a PCB.
Meanwhile, an embedded multilayer ceramic electronic component is installed in a core part within a board, so a nickel/tin (Ni/Sn) plated layer on external electrodes thereof is not required, unlike a general multilayer ceramic electronic component mounted on a surface of a board.
Namely, since external electrodes of an embedded multilayer ceramic electronic component are electrically connected to a circuit within a board through a via made of a copper (Cu) material, a copper (Cu) layer, rather than a nickel/tin (Ni/Sn) layer, is required to be formed on the external electrodes.
In general, external electrodes may include copper (Cu) as a main ingredient, but since external electrodes include glass, a component included in the glass may absorb a laser in the event of laser beam machining to form a via within a board, making it difficult to adjust a process depth of the via.
For this reason, a copper (Cu) plated layer is separately formed on external electrodes of an embedded multilayer ceramic electronic component.
Meanwhile, an embedded multilayer ceramic electronic component may be installed in a printed circuit board used in a memory card, a personal computer (PC) main board, various radio frequency (RF) modules, thereby significantly decreasing a size of a product as compared with a multilayer ceramic electronic component mounted on a board.
In addition, since the embedded multilayer ceramic electronic component may be disposed to be very close to an input terminal of an active device such as a micro processor unit (MPU), interconnection inductance due to a conducting wire length may be decreased.
An inductance decrease in the multilayer ceramic electronic component embedded in the board is merely due to the decrease in interconnection inductance obtained by a unique arrangement, that is, an embedded scheme. Equivalent series inductance (ESL) improvement in a multilayer ceramic electronic component to be embedded in a board has still been needed.
Generally, in the case of a multilayer ceramic electronic component to be embedded in a board, a current path in the multilayer ceramic electronic component needs to be shortened in order to decrease the ESL.
However, since the copper (Cu) plated layer is separately formed on the external electrodes of the embedded multilayer ceramic electronic component, a plating solution may permeate into the external electrodes, whereby it is not easy to shorten the current path in the multilayer ceramic electronic component.
In addition, in accordance with an increase in a speed of an application processor (AP), the use of a multilayer ceramic electronic component embedded in a board has increased and the number of components to be embedded in a package has increased, whereby an occupied area has continuously increased.